day01: optimizations

src/historian_hysteria.gleam

@@ -5,41 +5,39 @@ import gleam/result
 import gleam/string
 
 fn parse_line(line: String) -> List(Int) {
-  use line <- list.map(string.split(line, "   "))
-  result.unwrap(int.parse(line), 0)
+  use a <- list.map(string.split(line, "   "))
+  result.unwrap(int.parse(a), 0)
 }
 
 fn dist(scans: #(Int, Int)) {
   int.absolute_value(pair.second(scans) - pair.first(scans))
 }
 
+fn freq_score_gen(ys: List(Int)) {
+  fn(x) { x * list.count(ys, fn(y) { y == x }) }
+}
+
 pub fn solve_a(input) -> Int {
   input
   |> string.trim()
   |> string.split("\n")
   |> list.map(parse_line)
   |> list.transpose()
-  |> list.map(fn(x) { list.reverse(x) })
-  |> list.map(fn(x) { list.sort(x, int.compare) })
+  |> list.map(list.sort(_, int.compare))
   |> list.reduce(fn(x, y) { list.map(list.zip(x, y), dist) })
-  |> result.unwrap([])
-  |> list.reduce(int.add)
+  |> result.map(list.reduce(_, int.add))
+  |> result.flatten()
   |> result.unwrap(0)
 }
 
-fn similarity(x: Int, y: List(Int)) {
-  x * list.count(y, fn(z) { x == z })
-}
-
 pub fn solve_b(input) -> Int {
   input
   |> string.trim()
   |> string.split("\n")
   |> list.map(parse_line)
   |> list.transpose()
-  |> list.map(fn(x) { list.reverse(x) })
-  |> list.reduce(fn(x, y) { list.map(x, fn(item) { similarity(item, y) }) })
-  |> result.unwrap([])
-  |> list.reduce(int.add)
+  |> list.reduce(fn(x, y) { list.map(x, freq_score_gen(y)) })
+  |> result.map(list.reduce(_, int.add))
+  |> result.flatten()
   |> result.unwrap(0)
 }

test/historian_hysteria_test.gleam

@@ -1,4 +1,3 @@
-import gleeunit
 import gleeunit/should
 import historian_hysteria as day01